In a circumstance of extremely high accuracy, design requirements as are met by use of a wire electrical discharge machine. Also, a very close focus must be taken in the design of the holding systems and clamping pressures used in the holding system. With the clamping pressure causing the object being clamped to be moved away from the alignment surface, the moveable jaw is designed to apply an inward movement to the alignment surface as the vise jaw is receiving clamping pressure.
Also, the guide track the moveable jaw rides in is contoured in a way that directly holds the walls of the vise from moving in an outward direction which would change or distort the alignment surface. Such distortion would affect the locating and repeatability of the clamping location, thus changing the location or size of the parts being repeatedly made.
To otherwise combat this distortion, a qualified operator of a wire electrical discharge machine would have to go through a complete set-up for every part machined. The association set-up cost are not conductive to a productive manufacturing environment.
Also, due to the circumstance of working occasionally in very restrictive areas or with small workpieces, the vise must be constructed in a way that is not bulky or interfering with machine travel.
In U.S. Pat. No. 4,925,168 (hereinafter the ""168 patent) a stationary jaw constructed of a base with a section of the structure extending outward is shown. Extending from that outward section are two legs of the stationary jaw leading out and downward and connecting to a thin wall. This structure may assist in holding the workpiece close to the alignment surface, but the spring structure of the legs could prevent true reliability for location and keeping the workpiece square while applying clamping pressure. The ""168 patent incorporates a leveling head to correct the tilt of the workpiece.
Also in the ""168 patent the channel that the moveable jaw travels through is constructed of abutment surfaces at an incline that assist in holding the side walls and preventing them from being forced out during clamping pressure. This will affect the parallel and squareness of the alignment surface. This distortion may cause problems with the accuracy requirements imposed upon the process.
The use of a radiused contour directly holds and supports and outer walls to prevent any outer flexing of the vise. Also, this contour will give more locating surface and more radiused corners which are a proven way to combat cracking conditions that would be of concern in any thin construction. These vises are of a thin construction due to the need to always minimize interferences in the work area.
In the design there are improved contact surfaces in the slide channel that directly hold and support the side walls of the vise during the clamping operation. As the clamping action is applied to the vise, it commonly causes a pushing force in an outward direction. This movement would interfere with the quality expected in a wire electric discharge machine.
In the design of our moveable jaw a sliding insert that will always stay in solid contact with the moveable jaw is provided. This solid contact prevents any twisting or spring tilting action during clamping. With the angle which the insert is set in the moveable jaw, the clamping pressure will cause the insert to draw down in the vise which will aid in drawing the workpiece tight to the alignment surface of the vise.
With the combined improvements of the slide channel for the moveable jaw and the design of an insert in the moveable jaw a design of a precision clamping vise that offers both quality and long service to the users is provided.